Inasmuch as rear projection video apparatus, e.g., a liquid-crystal rear projector (hereinafter referred to as "liquid-crystal rear projection television") incorporating video devices including a liquid-crystal display portion (hereinafter referred to as "LCD"), an optical unit including a projection lens, a light source, a mirror, etc. and having a screen attached to an upper front thereof has been proposed.
A liquid-crystal rear projector is able to reduce its depth and to widen its screen, and such a liquid-crystal rear projector can be easily enlarged in size compared with a television receiver using a cathode-ray tube (CRT).
FIG. 1 of the accompanying drawings shows such liquid-crystal rear projector.
A liquid-crystal rear projector, generally depicted at reference numeral 1 in FIG. 1, comprises an upper cabinet 2 and a lower cabinet 3. The upper cabinet 2 houses a screen 4 disposed at the front surface and a mirror 5 for irradiating the screen 4 with rays of light of an image.
The lower cabinet 3 includes an optical unit 7 having a projection lens 6, a lamp house portion for irradiating the optical unit 7 with light and a control portion (not shown) for controlling the optical unit 7.
The lamp house portion 8 incorporates a lamp for generating light, although not shown. Since the incorporated lamp generates a heat of high temperature, the lamp is accommodated in the liquid-crystal rear projector from the rear side and hence cannot be easily exchanged, thereby protecting a user of the liquid-crystal rear projector from danger.
However, as described above, the lamp is set in and/or removed from the lamp house of the liquid-crystal rear projector from the rear side of the television receiver and therefore cannot be easily changed. As a result, when a rear projection type video apparatus is enlarged in size, such large-sized rear projection video apparatus faces a problem when the user changes a lamp, i.e., it is troublesome for the user to exchange a burned out lamp.
A life of a lamp used in the rear projection type video apparatus is not long compared with a television receiver having a CRT. If the lamp is burned out, then the rear projection type video apparatus cannot display a picture at all. Moreover, the rear projection type video apparatus become very much unreliable if it is repaired many times.
Furthermore, if the lamp is burned out, then such burned out lamp has to be exchanged by a technical expert because the lamp generates a heat of high temperature. Thus, such burned out lamp is not so easy to be exchanged, thereby requiring plenty of time for changing the lamp. Therefore, the user is unable to watch a desired picture for a long period of time compared with the case of the television receiver having the CRT.
As described above, a large-sized rear projection type video apparatus encounters the above-mentioned problem that a lamp, although it is indispensable for such rear projection type video apparatus as a light source, is not so long in life span and is not so easy to be exchanged when it is burned out.